King of the Hill

Key Question:

What was the objective? What were you trying to accomplish? 
-The objective was to make a self-propelled car that would effectively travel up the ramp and stop the opposing car from getting over. I was trying to accomplish stopping the other opponent by making a car that would be built well enough with enough force to make it over the ramp and stop the opponent.

Investigating:

Plan:
We are planning to make our car frame out of lightweight wood and to use CDs as the wheels. We will use a mouse trap for the force to make the car accelerate up the hill. We will attach a string to the mouse trap and wrap the other end around the wooden dowel attached to the back wheel. When the mouse trap pulls on the string, the string will spin the dowel forcing the wheels to move.





Materials: 
- 4 CDs (free from house)
-1 mouse trap ($1.00)
-rubber bands ($2.00)
-wooden dowels ($3.00)
-eye hooks ($4.00)
-balloons ($1.50)
-string (free from house)

Analysis: 

First Race: We won our first race, but barely. Our car was slower up the hill so the other car made it up first, but our car knocked it back down. whew!I was nervous because we almost lost, but excited that we won. I knew it was going to be a close race from the beginning because our cars were built very similar.

Second Race: Going into the second race, I was not expecting to win considering the outcome of our first race. The opponent's car was much bigger and looked a lot stronger than ours, so I wasn't surprised by the outcome, of us losing. I wasn't that disappointed because we made it into the second round and already won one race.

Developing a Model: 

We made our car lightweight and quick, that would still be able to take a hit. We made our car out of a mousetrap, CDs, and wood dowels. We used a mouse trap as the force to move the car and attached a string from the mouse trap to the wooden dowel that controlled the back wheels. This way the mouse trap forced the string to unravel, spinning the wheels. We also used metal eye hooks to connect the mouse trap to the wooden dowels and used balloons to cause friction with the ramp. The value of the force will cause our car to accelerate so it will go from moving at a constant speed to speeding up.

Evidence:

Our car didn't make it past the second round. Our car just wasn't built strong enough to beat the other car made out of wood. It could run good and make it up the hill, without the other opponent pushing it down. The force of the other car out pushed the force of our car making the net force/ acceleration towards ours, bringing us back down the hill. 
     Most of the winning cars were made out of wood. These cars were able to propel themselves up the hill and take hits from the other cars without any damage. The wood made them able to withstand the impact but also go at a good speed which the other car was also moving in. I think a successful car needed stability and speed.
     If I could change my car I would add more weight and distribute it properly. I think our car was too light so the heavier cars just pushed it around. I would make it out of a different material, such as wood to make it more durable. 

good work!

Ticker Tapes

Key Question: What is the relationship between position and time for a cart rolling down a ramp? What is the relationship between velocity and time for a cart rolling down a ramp?

Investigating:

                           

     

Explanation- The ticker timer uses a carbon fiber to show the change in velocity over time by creating ticks. The ticker timer makes 6 ticks per 1/10 of a second. We attached a piece of paper to the back of a cart and put the other end through the ticker timer so we can see the marks it makes and measure the velocity change in the cart as the time increases. The cart travels at a downward slope so it gradually speeds up. This is shown by the dots getting further and further apart since they are marked at even time intervals. Using the ticks, we were able to create data to turn into a graph. To make this data, we counted every 6 dots because that represents a tenth of a second. At every 6th dot we measured how far it is from the first dot. By doing that we were able to tell how far the cart traveled at every tenth of a second.  good

Data Analysis: 

Time (seconds)	Position (centimeters)
0.1 seconds	1.5 centimeters
0.2 seconds	4 centimeters
0.3 seconds	7.3 centimeters
0.4 seconds	11.5 centimeters
0.5 seconds	16.5 centimeters
0.6 seconds	22 centimeters
0.7 seconds	28.5 centimeters
0.8 seconds	35.5 centimeters
0.9 seconds	43.2 centimeters
1.0 seconds	52 centimeters
1.1 seconds	61.2 centimeters
1.2 seconds	71.5 centimeters
1.3 seconds	82.3 centimeters

Verbal Model: As the time increases, the position increases at an increasing rate. 

Math Model: x=(38cm/s^2)t^2 

Description: The cart is moving with an increasing velocity in a positive direction.

Velocity vs. Time Graph

Verbal Model: As the time increases, the velocity increases proportionally.
Math Model: Vf=at+Vi       

                        a=(cm/s)/s
Slope: Acceleration ((cm/s)/s or cm/s^2)
Y-Intercept: The initial velocity 

excellent
  Models:

• The new equation for the Position vs. Time graph is Δv x=(1/2)at^2. In this equation Δv  xis the area under the curve. This area represents the total distance traveled during the total amount of time. The new equation of the velocity graph is Vf=at+Vi. This is the derivative of the position graph and allows us to find the velocity equation. "a" represents acceleration, "t" represents time, "Vf" represents the final velocity and "Vi" represents the initial velocity. 

why is this font so weird??  and where did we get these equations - how do they relate to what you saw in lab?

Explaining: 

• No, the numbers for the constants and slopes were different for each group. This is because every group used a different ramp, so each group had a different incline. This causes the constants and slopes to be different because the car sped up at different rates, depending on the steepness of the incline.
• Errors in my experiment could have included using the dots either at the very beginning of the tape or at the very end. This could have messed up my data because during those times, the car wasn’t moving the way it was supposed to. We could have started the timer before we let the car go or stopped the timer after we already slowed down the car, messing up the distance between the dots, which shows how far the car traveled for that certain 
• Another idea to test regarding acceleration is the opposite of this. Instead of speeding up, what if the car was slowing down. Or another experiment could be to use the same ramp with the same incline but add weight to the car to test how weight affects the acceleration. both good ideas

Marshmallow Shooter

Experiment 1:

Key Question- How does the length of the tube affect the distance traveled by the marshmallow?

IV: Length of the tube
DV: Distance traveled
CV: How far from the ground and the force of the blow

Procedure-We will use three different tubes with the lengths of 29.5 cm, 25.4 cm and 12.7 cm. We will make a line of yard sticks on the ground on the centimeters side so we will be able to measure how far the marshmallow traveled. Our starting position will be at 0 cm. The marshmallow will be located on the side of the tube closest to the mouth and the other end of the tube will be located at 0 cm. The blow will be the same force each time. We will then measure how far the marshmallow traveled in centimeters. This experiment will be taken place three times for each of the three different tube lengths and find the average per size. excellent!

Analysis: 

Size of the tube (cm)        How far the marshmallow travelled (cm)
        29.5 cm                                           256.5 cm
        (large)                                             254 cm                                          
                                                                241.3 cm
                                                                Average: 250.6 cm

Size of the tube (cm)        How far the marshmallow travelled (cm)
        25.4 cm                                           157.5 cm
        (medium)                                        165.1 cm                                          
                                                                167.6 cm
                                                                Average: 163.4 cm

Size of the tube (cm)        How far the marshmallow travelled (cm)
        12.7 cm                                           94 cm
        (small)                                            101.6 cm                                          
                                                               106.7 cm
                                                                Average: 100.8 cm

The data shows that if the marshmallow is blown with an equal force, the marshmallow will travel further as the tube gets larger.
good
Experiment 2:

Key Question- How does the height of the tube from the ground affect how far the marshmallow travels?

IV: Height from ground
DV: Distance traveled
CV: Pressure of blow and length of tube

Procedure-  In our second experiment we will test how the height from the ground will affect the distance traveled by the marshmallow. We will start at 0 cm every time, keep the length of the tube the same and the force of the blow the same, and we will start with the marshmallow close to our mouths. We will collect three lengths for each height and find the average. The heights we will use are 5'2, 6'8 and 2'6.

Analysis: 

Height From Ground                                Distance Marshmallow Traveled
          5'2                                                                    132.08 cm
          6'8                                                                    162.56 cm
          2'6                                                                    48.26 cm

The data showed the higher the tube is from the ground, the further the marshmallow will travel.
good
Experiment 3: 

Key Question- How does the force of the blow affect how far the marshmallow travels?

IV: Force of the blow
DV: Distance traveled
CV: The height from the ground and the length of the tube

Procedure- In the third experiment, we will discover how the force of the blow affects the distance traveled by the marshmallow. We will start off at 0 cm each time with the marshmallow close to our mouth and the length and height of the tube will stay the same while the only thing changing will be the force of the blow. We used small, medium and large forces and tested each force three times and found the average.

Analysis:

Force of Blow                                         Distance Marshmallow Traveled
      Small                                                                    43.18 cm
      Medium                                                               132.08 cm
      Large                                                                   172.72 cm

verbal statement for this one??

Conclusion: 
             In the first experiment, we tested how the length of the tube affected the distance. This is another way of testing the time. We kept the marshmallow in the tube closest to our mouth. We made a conclusion that the longer the tube is, the further the marshmallow will travel because it will have a higher velocity. The velocity will grow with the length because it will have more time more time for what?. The more time it has the higher velocity it will have. This is proven in the equation J = Δp F x t= mΔv. We discovered that the higher velocity the marshmallow has, the further it will travel.              In the second experiment we tested how the height from the ground affected the distance the marshmallow traveled. The velocity, mass, force and time were the same with only the height changing. The higher the tube was, the further the marshmallow traveled. This is only because the marshmallow had more time in the air to travel, but it left the tube with the same velocity and momentum. It had more time in the air but the same amount of time with force applied to it, that is why the time in the equation is equal.       kind of, but seems confusing....  needs clarified      In the third experiment we tested how the force of the blow affects the distance the marshmallow traveled. We discovered that the greater force put on the marshmallow, the further it will travel. This is proven in the equation F x t= mΔv. The stronger the force, the higher the velocity and momentum causing the marshmallow to travel further.        Our experiments would have been more accurate if we had a machine that blew for us so we knew it was constant when it was supposed to be in experiments 1 and 2. Also if we could see exactly where the marshmallow landed our data would be more accurate. why couldn't you see exactly where it landed?  how could you fix that?

pretty good...  height needs explained a little more, and all could be clarified a bit...